Power snowplow



Nov. 29, 1932. J. B. WOODBURY ET AL POWER SNOWPLOW Filed Dec. 28. 1929 3Sheets-Sheet 1 INVfA/ToRS.

1mm 23. moodbur Georye 0.6oule Nov. 29, 1932. J. B. WOODBURY ET AL POWERSNOWPLOW Filed Dec, 28, 1929 3 Sheets-Sheet 5 fit rney.

Patented Nov. 29, 1932 UNITED STATES PATENT OFFICE JOHN B. WOODBURY ANDGEORGE G. SOULE, OF SOUTH PORTLAND, MAINE, ASSIGNORS TO MAINE STEELPRODUCTS COMPANY, OF PORTLAND, MAINE, A. CORPORATION OF MAINE POWER SNOWPLOW Application filed December 28, 1929. Serial No. 417,1?3.

In the manipulation of snow plows, especially where there are adjustablelateral wings, as well as an adjustable'nose, the control of such partshas become of very great importance. This is particularly true in thecase of motor driven equipment where the aim is rapidity of operation aswell as high power. 7

In the clearance of snow, especially on highways where conditions changefrom point to point, the more rapidly moving motor driven plow needs tobe constantly adjusted and with an increased celerity over hand methods.If this is not possible the plow must either be slowed down to give timefor wing or nose adjustment, or else adjustm'ents must be slighted, withcorrespondingly imperfect results. For these reasons it has beenproposed to provide power adjustments and the engine of motiveequipment, as for example tractor or truck, offers a ready source forsuch power.

The trouble has been that the rig through which the plow and tractor arebrought together is necessarily one in which considerable flexibilityand freedom of movement must be provided. It has been found difficult toprovide a practical working basis sufliciently simple to afford amechanical control with suflicient detachability to permit the tractorto be removed from the plow where it is desired to utilize the tractorfor other purposes.

The present invention contemplates equipment having certain novelfeatures and advantages among which the following may be noted. For manyreasons a so-called hydraulic control has been deemed desirable as itaffords both the needed power and the wide range of flexibility whichroad conditions call for.

There are two main reasons for providing hydraulic controls on snowplows. The comfort and safety of the operator are very practical factorsin working efiiciency. With hand operated plows one or more operatorsequipment.

necessity standing much of the time on a slippery and unsteady platformviolently agitated by the movement of the tractor over open ditches androu h ground. This made the work not only difficult to perform, butinvolved considerable risk to the operator.

Another reason for providing hydraulic control is the demand for greaterproductivity in snow plowing. With the develop,- ment of greatertractive power in motor equipment, wings may be designed of greaterlength to make wider cuts and consequently must be heavier to withstandthe strains. The operation of such wings by hand is slow and exhausting.

Mechanical control such as hydraulic power is also of great importancein that it makes possible a high quality of snow plowing at greaterspeed. Roads may be plowed cleaner and more effectively by such controlthan by .hand.

The matter of speed of adjustment is important in that snow conditionsare extremely variable due to different configurations of the ground,varying widths of road, and the action of wind which may blow one pieceof ground bare and pile the blown snow in high drifts just beyond.

On account of this variable condition it is necessary within very shortdistances to change the elevation of the wings from a position in whichthey scrape close to the ground to clear a maximum width of light snowto a position high in the air to permit the plow to penetrate deepdrifts or to push back on one sideorthe other high side banks.

This necessity for changing wing position in actual practice isextremely frequent and if the change can only be accomplished by a slowhand control it becomes necessary to slow down or stop the tractor ortruck the corresponding frequency to give time to make v theadjustments. With hydraulic equipment the wing is raised or lowered in avery few seconds and the motor equipment can be driven at its highestoperating speed without delay for its adjustment which very largelyincreases the productivity of the This case of operation goes to makebetter and more eflicient work as it avoids the tendency of the operatorto place the wings in a middle position and to avoid re-adjustment asfar as possible which would mean that the wings would not plow cleanwhere the snow was light and are often carried suspended midway withoutdoing any work at all, all of which tends towards improper roadconditions. The foregoing applies to both tractor operated and truckoperated snow plows.

Such a system requires a pump and in order to utilize the power of thetractor motor itself, it is desirable that the pump be located on thetractor itself. One difliculty has been in connecting a pump on atractor with the hydraulic cylinderon the plow without having suchconnections subjected to destructive strains due to the motion andvibration incident to the relative movements of the tractor and plow.

One important concept of the present invention lies in mounting thehydraulic cylinder on the tractor itself so that permanent pumpconnections may be made without dan-' ger of strain and leakage.

The invention furthermore conceives of a basis of connecting suchhydraulic control with the wing and nose hoists of the plow so that theymay be readily connected and disconnected and yet when connected operatewith a maximum of efliciency and ease of control.

.The ease and versatility of the control is,

also of obvious importance. As before stated the rapidly moving plowmust be rapidly and accurately adjusted to meet the variant conditions.Furthermore, as a. practical matter due to the usual condition of coldor storm, it is necessary that the operator be afforded every facilityto do his work properly in spite of the handicaps imposed upon Thepresent invention therefore contemplates a system of control by whichwing and nose hoists may be quickly and positively operated either toraise, hold, or lower the plow part or parts to be adjusted.

In this connection another improvement is afforded by the presentinvention. In hydraulic controls where the pump is continuously operatedfrom the tractor motor, a considerable amount of horse power is requiredif the hydraulic control is held to its work incessantly. In solvingthis problem the present invention has maintained the complete andimmediate availability of reserve power without actually drawingcontlnuously on the motor and thus effects a very considerable saving inthe power of the tractor itself and its fuel consumption.

In such systems, furthermore, where oil is circulated as a fluid medium,difficulty has been experienced with back pressures and the presentinvention avoids this difliculty.

The inventions involved are capable of various embodiment, but for thepurposes of illustration a typical equipment will be shown in theaccompanying drawings, as both illustrative of the principles and as initself of proven elficiency and worth. Throughout the specification anddrawings like reference characters are employed to indicatecorresponding parts.

As illustrative of the present invention'the accompanying drawingsillustrate an embodiment which shows both the principle and mechanicaldetails of equipment, according to the invention. In these drawings Fig.1 is a perspective of a tractor driven plow equipment viewed from therear end.

Fig. 2 is a detail of the nose.

Fig. 3 a somewhat diagrammatic v1ew of the hydraulic control.

Fig. 4 a sectional View of the relief valve.

Fig. 5 a fragmentary detail in rear elevation and partial section of thehydraulic wing hoist.

Fig. 6 is a rear elevation of the nose hoist.

Fig. 7 is an elevation of the differential drum for the wing hoist.

Fig. 8 is a transverse section of the control valve cylinder block onthe 'line 8-8, of Fig. 9.

Fig. 9 a section on the line 99, of Fig. 8.

Fig. 10 a section on the line 1010 of Fig. 9. Figs. 8 to 10 inclusiveshow the valve block only, without sleeves or valves.

Fig. 11 is a longitudinal section of a valve completely assembled andshown in holding position, section being taken on the line 11 11,-ofFig. 9. i a

Fig. 12 shows the valve plunger in position to allow the oil to pass tothe jack cylinder.

Fig. 13 is a corresponding section but showing the relief of the oilin-a cylinder to permit lowering;

Fig. 14 is a similar section of the relief valve assembly taken on theline 14-14, of Fig. 9, the valve plunger being broken longitudinally andshown in two positions.

Fig. 15 is a section on the line 1515, of Fig. 11, and

Fig. 16 a transverse 16-16, of Fig. 11.

In the drawings we have shown an equipment which as in Fig. 1 isparticularly adapted to tractor use. In that figure the tractor isindicated as T and removably disposed within the frame of the plow.

The frame may be variously constructed, but as shown consists oflongitudinal base or runner members 1 and the transverse beam 2. At theends of the longitudinal members are erected rear columns 3 and frontcolumns 4.- These are connected transversely by front and rear beams 5and 6 and side beams 7. The rear beam 2 is removable to permit of thetractor entering the frame work of the plow.

section on the line This constitutes the general frame of the plowproper. Theplowing members are indicated as a nose 8 and wing members 9.The wings 9 are slidably mounted on the columns 4 so as to be verticallyadjustable and also pivoted to tilt on their connection so as to beangularly adjustable with reference to the road surface.

The nose member 8 is mounted at the forward ends of the runners 1 of theplow frame. It is vertically adjustable relative to said plow frame bythe side levers 10 which are pivoted as at 10 'on fulcrums carried bythe frame of the tractor. The general frame structure of the plow islinked to the tractor by a member 100 which is connected with theplatform member on the tractor and is pinned to a pair of ears 101 onthe rear beam 2 of the frame of the plow. The plow frame therefore ispivotally connected to the tractor at this point and its adjustments aremade from this point as a pivotal basis.

The wings 9 and nose 8 are the plowing factors requiring the ready andeasy adjustment above referred to. The controls comprise as shown atriple cylinder hydraulic jack mounted on a base to form a unit andcarried on an extension platform on and at the rear of the tractor. Ofthese the jack" 11 is for the nose hoist and has its plunger 12 providedwith a yoke 13. To this are attached cables 14 (see Fig. 6) which passunder sheaves 15 spaced apart on the base 311C secured at their otherends to the cross bar 10 of the levers 10 at some distance apart tomaintain balance and equalization. The jack 11 therefore has a balancedcontrol of the nose levers 10 so that the nose 8 can be raised orlowered as desired. The control of 32'and 33. On these are wound thecontrol cables of the wing hoists by which the wings 9 are raised orlowered as desired.

These hoists consist of a front end cable 34 and a rear end cable 35.The drums 32 i and 33 are so proportioned that the front end cable 34 istaken up at about one-half of the speed of the rear end cable 35.

The jack cylinders 11 and are connected with a fluid pressure source asthe pump 80 which supplies the cylinders 11 and 20 under the control ofa valve system operated bv levers 40 located in the cab of the tractorT.

This valve control system is diagrammati cally shown in Fig. 3 and isconnected up as follows. Y

, plunger.

The supply tank S stores surplus of the operating fluid beyond thatinthe cylinders which for this work is a low temperature oil. The pump80 takes this fluid supply through the intake 81 and delivers it underpressure to the line 83. In the line 82 is a pressure control 90including. a valve 91 adjustably held to its seat by a spring 92. -Uponresistance to passage of oil in the main delivery line 83, this valveopens up the general bypass lines 82 and 84, to which the upper ends ofthe cylinders 11 and 20 are connected for relief. The by-pass line 84returns to the storage reservoir S.

The main or pressure operating line 83 from the pump 80 is provided witha valve control. valve cylinders, 41, 42, 43 and 44, within whichoperate sliding valves or plungers 41 42 43 and 44 (the two latter notshown, but in reality duplicates of 42 (see Figs. 11 to 14). 41 is theby-pass or idlingvalve, 42 controls the right wing hoist, 43 the leftwing hoist, and 44 the nose'hoist.

The valve 41 is simply a by-pass which when opened permits the pump 80to operate with the minimum of resistance. The plungers 42 43 and 44control the fluid pressure supply to the lifting jack cylinders 11 and20. controls the supply line 45 to the nose hoist cylinder 11. The othertwo valve cylinders 42 and 43 control the lateral wing hoists byconnections 46 and 47, respectively.

The cylinders 41, 42, 43 and 44 as shown in Fig. 9 are incorporated-in acasting 50 and constitute the housings for the valves 41 to 44 Thesecylinders are arranged in a parallel disposition and having a commonchamber 51 which extends midway of the casting 50 and as at A is inconstant communication with the line 83 from the pump 80.

Each of the valve cylinders connects at its end with a common passage 52at the end of the casting 50, this passage or chamber being in opencommunication as at R with a pipe line and a branch 61 to the intake 81of the pump. The line 60 extends also to a branch 62 entering the tankS. The three cylinders 42. 43 and 44 which control the two wing hoistjacks 20 and the nose hoist jack 11 are of the same construction and areshown in section in Figs. 11, 12 and 13, these figures representingdifferentpositions of the valve In these cylinders the sleeves 53 areprovided with ports 54 and 55 which at a certain position of theirplungers permit communication respectively between thev common oilpressure chamber 51 and the re- As shown in Fig. 3 the valve cylinder44- In this installation there are four spective connections D with 45,46 and 47 extending to the jack cylinders.

Referring to Fig. 11 which is a section through the r valve assembly 42controlling the elevating' of the right, wing, the ports 55 connect withthe surrounding individual chamber 42 into which the line 46 is tapped.

The valve plunger 42 (Fig. 11) is provided with the usual leather cuppackings 60, 61, 62 and 63 which are adj ustably spaced on the stem 64to provide opposite pairs and constituting shut-offs between the commonpressure feed chamber 51 and the delivery to the jack which it controls.The valve p! .mger 41 of the valve cylinder 41 is somewhat similarlyconstructed but its piston packing cups 71 and 72 define only a singlepassageway which may block off the supply chamber 51 as-when in theposition shown in the upper part of Fig. 14 or may open up the chamber51 to the relief chamber 52 when it is desired to permit the oil toby-pass, as illustrated in the lower position of the plunger.

With the parts positioned as in Fig. 11 the valve in its cylinder 42 ispositioned so as to cut off the intake from. the passage 51. In thisposition no fluid is delivered to the jack which it controls. This,therefore, is the posit-ion'of the valve .both prior to the operation ofany jackand its position after a jack has been operated to any desiredposition which is to be maintained.

In order to operate the jack the' valve is advanced to the positionshown in Fig. 12 which connects up the pressure supply from the commonpassage 51 with its delivery chamber so that the oil passes through theline 46 (connection D) to operate the jack 20 which in this case is thejack operating the right wing. If it is desired to lower the wing thevalve is withdraw to the position shown in Fig. 13 in which the chamber51 is cut off and the ports 55 uncovered, permitting the oil to beforced back from the jack and escape through the passage 52 to theconnections and 61 and so back to the pump.

Each ofthe jacks is provided near its top with a pressure-relief plpe 85which connects up with the return line 84 which leads to the tank S. Theobject of this construction is to provide relief from the oil pumppressure acting on the bottom of the piston 86 when the latter rises toits limit of upward movement in the jack cylinders 11 and 20 whichposition is slightly above the opening out of the connections at 85.This line is also connected with the line 82 from the relief valve 90which has been previously described.

Through such a control either or both wing and nose may be raised orlowered or held in any desired position, rapidly and with the minimumeffort on the part ofthe operator. The by-pass control relieves the pump80 which is driven by the motor from unnecessary work and therebyreduces the burden on the tractor motor. The connections permit thetractor with its hydraulic jack unit to'be withdrawn by merelydisconnecting the rope members at any convenient point as by sockets(not shown) and by removing the connecting pins (not shown) whichconnect the nose levers to the nose, and unshackling the cross member 2of the plow frame. In reassembling the equipment the rear frame of theplow is opened up as at 2, the tractor driven in, the hoists connectedup and the nose connectedv with the levers 10 which are carried by thetractor.

What we therefore claimand desire to secure by Letters Patent is 1. In asnow plowing equipment, a plow comprising a frame, nose and wing membersvertically adjustable thereon relative to said frame, hoists "forraising and lowering said nose and wing members, a plurality ofhydraulic cylinders connected with said hoists, a motor. driven vehicleremovably located within the plow frame, a hydraulic cylinder controlunit independent of the plow frame disposed on the rear of the vehicleand operativly connected with said hoists and including control meansfor filling or emptying any cylinder orfor by-passing the oil when acylinder is filled, and independent means for by-passing the oilregardless of the cylinder condition.

2. In a snow plowing equipment, a plow comprising a frame, nose and wingmembers vertically adjustable thereon relative to said frame, hoists forraising and lowering said nose and wing members, a motor driven vehicleremovably located within the plow frame, a hydraulic control unitindependent of the plow frame disposed on the rear of the vehicle andoperatively connected with said hoists and including a pump, a supplytank, a plurality of cylinders connected to said pump and to said tankby connections including connections from the pump to each cylinder andfrom the cylinders to the tank, control means for filling or emptyingany cylinder or for, by-passing the oil when a cylinder is filled, andindependent means for by-passing the oil regardless of the cylinderconditions.

3. In a snow plow equipment, a plow comprising a frame, nose and wingmembers adjustable relative to said frame, hoists for" raising andlowering said members, a motor driven vehicle removably located withinthe plow frame, a motor driven hydraulic control independent of the plowframe and mounted on the vehicle, and means for connecting the hoistsand the hydraulic control.

4. In a snow plow equipment, a plowcomprising a frame, nose and wingmembers adjustable relative to said frame, hoists for raising andlowering said members, a motor driven vehicle removably located withinthe plow frame, a motor driven hydraulic control independent of the plowframe and mounted on the vehicle, "and means for connecting the hoistsand the hydraulic control,

and means for detachably connecting the plow frame to the vehicle.

5. In a snow plow equipment, a plow comprising a frame, nose and wingmembers adjustable relative to said frame, hoists for raising andlowering said members, a motor driven vehicle removably located withinthe plow frame, a motor driven hydraulic control independent of the plowframe and mounted on the vehicle, and means for connecting the hoistsand the hydraulic control, and means for detachably connecting the plowframe to the vehicle through the hoists.

6. In a snow plow equipment, a plow comprising a frame,'a noseadjustable relative to said-frame, a nose lever for raising and loweringthe nose, a motor driven vehicle remova'bly located within the plowframe, and pivotally' supporting said nose lever, a motor drivenhydraulic control independent of the plow frame and mounted on thevehicle, and means for connecting thev lever and the hydraulic control.1

' 7. A propulsion unit for snow plows or the like comprising a motordriven vehicle, a hydraulic control unit independent of the-plow andcarried on the vehicle at the rear end thereof including a pump, asupply tank, a plurality of cylinders connected to said pump and to saidtank by connections, including connections from the pump to eachcylinder,

and from the cylinders to the tank, and a sliding three port valveincluded in each cylinder connection for filling or emptying anycylinder or for by-passing the oil from pump to tank when a cylinder isfilled, and indeendent means for by-passing the oil regardess of thecylinder condition, the by-pass ports of said valves having entry to acommon by-pass passage. I i 8. "A propulsion unit for snow plows or .thelike comprising a motor driven vehicle, a hydraulic control unitindependent of the plow and carried on the vehicle including a pump, asupply tank, a plurality of cylinders connected to said pump and to saidtank by connections includlng connections from V p the pump to eachcylinder, and from the cylinders to the tank, and a three port valveincludedineach cylinder connection for filling or emptying any cylinderor for lay-passing the oil from pump to tank when a cylinder is filled,and independent means for by-passing the oil regardlessofthecylinder'condition. I 9. In a snow plow equipment, a plow comdprising-aframe, a plow' nose vertically adjustable relative thereto, amotor vehicle removably located within said frame,- elevating means onsaid-vehicle and extended to the rearthereof and connected to? saidnose, a

wing vertically adjustable on said frame, a wing hoist carried on saidframe, a plural cylinder hydraulic control independent of the plow andon the vehicle, and connections between said control members and saidnose and wing hoists.

10. In a snow plow equipment, a plow comprising a frame, a plow nosevertically adjustable relative thereto, a motor vehicle removablylocated within said frame, elevating means on saidvehicle and extendedto the rear thereof and connected to said nose, a. wing verticallyadjustable on said frame, a wing hoist carried on said frame andextended to the rear thereof, aplural cylinder hydraulic controlindependent of the plow and at the rear-of the vehicle, and connectionsbetween said controlmembers and said nose and Wing hoists.

11. In a snow plow equipment, a plow comprising a frame, a plow nosevertically ad'-" prising a frame, a motor vehicle removably I locatedwithin said frame, a wing vertically adjustable on said frame, front andrearflexible wing hoists carried on said frame-and extended to the rearthereof, a pair of drums 'of different diameter one for each of saidflexible hoists, an operating drum, said drums rotating together ahydraulic control independent of the plow and on'the rear of thevehicle, comprising a cylinder and piston, and a flexible connectionfrom said piston and wound on said operating drum.

13. In a snow plow equipment, a plow comprising a frame, a plow nosevertically adjustable relative thereto, a motor vehicle removablylocated within said frame, a lever fulcrumed on each side of saidvehicle and extended to the rear thereof, and connected at its forwardend to said nose, a wing vertically adjustable on said frame, flexiblefront and rear end wing hoists carried on said frame and extended to therear thereof, a

plural cylinder'hydraulic control independ ent of the plow and on therear of theo vehicle; a connection from the nose lever to one controlmember, differential drums on the rear of the frame, said drumsreceiving the front and rear hoists of the wing, an operating drum: forthe receiving drums, and a flexible connection wound on said drum inreverse to the winding of the wing hoists on the differential drums andconnected to one of the by draulic controls.

14. In a snow plow equipment, a plow comprising a frame, a plow nosevertically adj-ustable relative thereto, a motor vehicle removablylocated within said frame, a lever- I fulcrumed on each side of saidvehicle and extended to the rear thereof, and connected at its forwardend to said nose, lateral wings vertically adjustable on said frame,flexible front and rear end wing hoists for each carried on said frameand extended to the rear thereof, a plural cylinder hydraulic controlindependent of the plow and on the rear of the vehicle, a pair oflaterally spaced connections from the nose lever to onecentrally locatedcontrol cylinder, a pair of differential drums at each side of thevehicle rear, each drum pair receiving the front and rear hoists of oneof the wings, an operating drum on each drum pair and a flexibleconnection wound on said drum in reverse to the winding of the winghoists on the differential drums and connected to one of thehydrauliccylinders.

15. In a snow plow equipment, a plow member having adjustable snowhandling elements, and a motor driven propulsion member detachablyassociated therewith, power controls carried by the propulsion member inpermanent assembly therewith andindependent of theplow and detachablecontrol connections carried by the plow, whereby plow and propulsionmembers may be separated without disturbing the power control assembly.

16. In a snow plow equipment, a plow frame having adjustable snowhandling elements, a motor driven vehicle for propelling said plowframe, a plurality of hydraulic operating jacks mounted on said vehicleindependently of the plow frame, a pump line to said jacks, a valvedcontrol for the supply of each jack, and a valved by-pass all having-acommon connection to the pump line and all havinga common discharge, anda by-pass line from said discharge to said pump, each valved controlbeing operable to connect or disconnect the pump supply to its jackcylinder or to by-pass' its supplyto hold the jack piston at any desiredposition. I 17. In a snow plow equipment, a plow connected,respectively, to said wing hoist' and nose lifting element, and manuallyoperable controls also mounted on the vehicle and controlling therespective cylinders of said hydraulic unit.

19. A snow plow as claimed in claim 18 wherein the plural cylindercontrol unit is mounted on the vehicle at the rear thereof and themanually operable controls are also mounted on the vehicle adjacent thefront end thereof for convenient actuation from the drivers seat.

In testimony whereof we afiix our signatures.

JOHN B. WOODBURY. GEORGE C. SOULE.

frame having adjustable snow handling ele- 1 ments, amotor drivenvehicle for propelling said plowframe, a plurality of hydraulicoperating jacks mounted on said vehicle independently of'the plow frame,a pump sup ply line to said jacks, a supply control comprising a valvefor each, jack, and a valved by-pass and all having a common connectionc through the by-pass intake to the pump line and all having a commondischarge through the by-pass discharge into a by-pass line to saidpump, each'valved control being oper-' able to connect or disconnect thepump supply of its jack cylinder, and the "by-pass anticipating thecylinder supply to hold any jack piston at any desired position.

18. In a snow plow, a plow frame, a motor driven vehicle removablylocated

